Perforated box culvert

ABSTRACT

A box culvert is disclosed having a top panel, a first side panel, and a second side panel, and a base panel. The first side panel and second side panel extend from the top panel to the base panel. The base panel is configured to have a plurality of sealed holes. The sealed holes are configured to be unsealed. Installing the box culvert in a riverway allows a road or trail thereover, and water passage therethrough. Opening of a specific amount, position, and size of sealed holes creates unsealed holes in the base panel. The unsealed holes allows groundwater upwelling therethrough, configured specifically to the waterway. The upwelling caused by removal of the specific plugs promotes aquatic habitat, contributes to water quality improvements, and ameliorates disruption from the insertion of the box culvert.

CROSS REFERENCES TO RELATED APPLICATIONS

This application claims benefit of priority from U.S. ProvisionalApplication Ser. No. 63/326,068, filed Mar. 31, 2022, the entirecontents of which are incorporated herein by reference.

FIELD

This disclosure relates to a box culvert for water passage.

BACKGROUND

Culverts are physical structures placed in a waterway to allow a paththereover while allowing passage of water therethrough. The waterway maybe drainage water, river water, streams, or the like. By installing aculvert, water may flow through the culvert, leaving a road or trail topass over the water unencumbered.

Known culverts are manufactured in different cross-sectional shapes,physical sizes, and materials. Most often, culverts are made usingmetal—such as steel—or poured concrete. The specific height, width,depth, and shape of a culvert may be based on the size of trail orwaterway, the natural landscape, and any budgetary concerns. Culvertshaving a generally square or rectangular cross section are oftenreferred to as box culverts. Box culverts may generally be categorizedas open-bottom or closed-bottom. A closed-bottom culvert has a basepanel of concrete that sits atop a waterway base, while an open-bottomculvert does not have any base panel.

As well, some known box culvert designs have holes in the bottom tocapture specific types of material as it passes through, therebycreating a habitat that is desired by particular species.

Installation of culverts (and culverts themselves) can often disruptnatural habitats of watercourses, plants and wildlife. Accordingly, aculvert to promote natural habitats of watercourses, plants and wildlifeis desired.

SUMMARY

A box culvert for installation in a waterway or river is disclosedherein. The box culvert is a closed bottom box culvert, meaning the boxculvert has a base panel extending across a floor of the waterway orriver. The base panel may be configured to have a plurality of sealedholes. The sealed holes may be configured to be unsealed. Based on aparticular application or parameter of the waterway for installation,the sealed holes of the base panel of the box culvert may be unsealed.Removal of the seals allows for groundwater upwelling through the boxculvert.

Aspects of the present disclosure relate to a box culvert, comprising: atop panel; a base panel; and a first and second side panel extendingfrom the top panel to the bottom panel, wherein the base panel has aplurality of sealed holes, each hole configured to be unsealed.

Other aspects relate to a method of installing a box culvert,comprising: providing a box culvert having sealed holes in a base panel;selecting, based on a determination for an installation site, at leastone sealed hole to be opened; opening the seal of the selected at leastone sealed hole to be opened; and installing the box culvert.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments will be described, by way of example only, with reference tothe accompanying figures in which:

FIG. 1 illustrates a closed-bottom box culvert;

FIG. 2 illustrates a closed-bottom box culvert having sealed holes;

FIG. 3 illustrates the closed-bottom box culvert of FIG. 2 with allholes unsealed;

FIG. 4 illustrates the closed-bottom box culvert of FIG. 2 having someholes unsealed;

FIG. 5A illustrates a cross section of the closed-bottom box culvert ofFIG. 2 according to a first embodiment;

FIG. 5B illustrates a cross section of the closed-bottom box culvert ofFIG. 2 according to a second embodiment;

FIG. 5C illustrates a cross section of the closed-bottom box culvert ofFIG. 2 according to a third embodiment;

FIG. 6 illustrates the closed-bottom box culvert of FIG. 4 in aninstalled position;

FIG. 7 illustrates a method of installing the closed-bottom box culvertof FIG. 2 ; and

FIG. 8 illustrates a cross-sectional view of an installation of the boxculvert of FIG. 4 into a stream bed.

DETAILED DESCRIPTION

FIG. 1 is a box culvert 100 known in the prior art. Box culvert 100comprises a base panel 110, a top panel 120, a first side panel 130, anda second side panel 140 (collectively “panels”). Box culvert 100 mayhave a height h, width w, and depth d. First side panel 130 and secondside panel 140 may extend from top panel 120 to base panel 110 to formpassage 150. The connection between panels defines a passage 150 forallowance of water therethrough and a road over top panel 120. Althoughreferences may be made throughout this disclosure to rivers, it would beknown that any culvert may be used for other waterways or storm drains.Similarly, while roads may be mentioned, railways, paths, or any otherfeature may be placed over top panel 120. A box culvert is considered anopen-box culvert if it does not include a base panel 110.

FIG. 2 illustrates a closed-bottom box culvert 500. Box culvert 500includes base panel 510, top panel 520, first side panel 530, secondside panel 540. First side panel 530 and second side panel 540 mayextend from top panel 520 to base panel 510 to form passage 560.Specific environmental parameters, such as the size of the waterway togo through passage 560, or the road to go over top panel 520 maydetermine the specific height, width and depth of box culvert 500.According to some embodiments, base panel 510 may extend deeper into ariverbed at river input and output to form cut-off walls 550.

Base panel 510, top panel 520, first side panel 530, second side panel540, and cut-off walls 550 may be constructed from the same or differentmaterials. Example materials are concrete, aluminum, stainless steel,plastics, or any other suitably rigid material. If box culvert 500 ismade using concrete, the concrete may be reinforced, using structuralmaterial such as rebar. Base panel 510 may distribute the weight of toppanel 520, first side panel 530, and second side panel 540 along theriverbed on which the box culvert 500 in installed.

Box culvert 500 may have an inlet section and an outlet section ofpassage 560. Cut-off walls 550 may be placed, respectively, under inletsection and outlet section of passage 560. Cut-off walls 550 may besolid, and may further include vertical pins that are pinned and groutedto inlet and outlet section of passage 560. Cut-off walls 550 may beconnected to base panel 510 such that no ground water can seep throughcut-off walls 550 and into or out of the space below base panel 510 andbetween cut-off walls 550. Inlet cut-off wall may also include one ormore openings for groundwater to travel through inlet cut-off wall andinto the space below base panel 510 and between cut-off walls 550. Oneor more openings may include perforations, channels, holes or otherfeatures that allow groundwater to travel through inlet cut-off wall.Outlet cut-off wall may be impermeable, preventing groundwater fromtravelling through outlet cut-off wall.

Box culvert 500 has sealed holes 512 in base panel 510. Base panel 510,as illustrated, is configured with a plurality of sealed holes 512having variable diameters and positions. Sealed holes 512 may beidentified using a coordinate system. Sealed holes 512 may havepredetermined successively smaller diameters. For example, sealed holes512 may be manufactured in base panel 510 to be 60 cm wide, 50 cm wide,40 cm wide, 30 cm wide, 20 cm wide, 15 cm wide, 10 cm wide, 7.5 cm wideand 5 cm wide. While the illustrated example of box culvert 500 showsholes in decreasing size, according to some embodiments, the holes maybe in a different order.

Sealed holes 512 of box culvert 500 may be sealed using plugs 514. Plugs514 may be made of a natural material such as wood or cork, or asynthetic material such as concrete, rubber, plastic or Bentonite. Insome embodiments, plugs 514 may also be made of concrete, rubber, orfoam. Plugs 514 may be configured to be temporarily or permanentlyunsealed. Plugs 514 may be configured having a shape complementary tosealed hole 512, or may be tapered. For example, plugs 514 may becylindrical, conical, semi-conical or convex. Plugs 514 that are taperedmay provide additional force on base panel 510 to maintain the sealedconfiguration. In some embodiments, plugs 514 may vary in diameter,shape, length, orientation, and composition, such that plugs 514 are notidentical. Plugs 514 may be friction fit into sealed holes, or may beinserted with a sealant or adhesive such as wax, caulk, or any othersuitable material. Plug 514 may include handles or any other implementto assist with plug removal.

Sealed hole 512 may also be partially unsealed by only partiallyremoving plug 514. For example, sealed hole 512 may contain a nestedplug, such that an inner plug may be removed to partially unseal thehole and form unsealed hole 516. An inner ring plug may further beremoved from unsealed hole 516 to further unseal unsealed hole 516, andan outer ring plug may further be removed from unsealed hole 516 tofully unseal unsealed hole 516. It will be appreciated that differentconfigurations, with fewer or more inner plugs or inner ring plugs, maybe possible.

Box culvert 500 may be manufactured at a location remote from the sitein which box culvert 500 may be ultimately installed. Alternatively,parts of box culvert 500 may be manufactured at several locations, suchas at a manufacturing facility and also at the installation site.

Box culvert 500 may be manufactured using a pourable curing semisolidand negative mold. For example, box culvert 500 may be manufactured bypouring concrete into a pre-form structure. The preform structure may beshaped to a negative of the intended constructed base panel 510, andinclude plugs 514 temporarily affixed and positioned in a desiredarrangement. Once the concrete is poured, plugs 514 may be cast into thebase panel 510 for later removal.

According to an embodiment, sealed holes 512 may be formed while castingbase panel 510. In other embodiments, sealed holes 512 may be drilledinto base panel 511 and plugs 514 may be temporarily affixed andpositioned in base panel 510.

Box culvert 500 may be manufactured in multiple steps. For example, thebase panel 510 may be initially cast. After the base panel 510 of thebox culvert 500 is cast, the first side panel 530 and the second sidepanel 540 can be cast, connected to base panel 510. Once in place, thetop panel 520 may be cast connected to and extending between the firstside panel 530 and the second side panel 540.

According to another embodiment, box culvert 500 may be manufactured asa clamshell-type precast structure. For example, the first side panel530 may be cast, connected to top panel 520. Second side panel 540 mayalso be cast, but connected to base panel 510. First side panel 530 andtop panel 520 may then be connected to second side panel 520 and basepanel 510.

Cut-off walls 550 may be manufactured as separate pieces from the restof box culvert 500, such as base panel 510. Cut-off walls 550 may beinstalled first into stream or river bed. It will be appreciated thatthe stream or river must be dammed first before cut-off walls 550 may beinstalled. For example, cut-off walls may be embedded into trenches duginto stream or river bed sized to accommodate cut-off walls 550. Basepanel 510 may be place on top of cut-off walls 550 and affixed using themethods discussed above. Since base panel 510 may be level, cut-offwalls 550 may be embedded into trenches such that cut-off walls 550 arealso level. For example, a fine layer of gravel may be placed under thebottom of cut-off walls 550 in trenches to ensure that cut-off wallsremain level.

Base panel 510, as well as the other panels of box culvert 500, may besupported by cut-off walls 550. However, since cut-off walls 550 mayonly provide support at the inlet and outlet sides of base panel 510,base panel 510 may also be supported between the inlet and outlet sides.As will be discussed in greater detail below, a clear stone gravel packmay be installed between cut-off walls 550 and beneath base panel 510.Clear stone gravel pack may be layered such that it is also level withthe tops of cut-off walls 550, and can thus provide support for basepanel 510, as well as the other panels of box culvert 500, between theinlet and outlet sides. Base panel 510 may alternatively be otherwisesupported.

Cut-off walls 550 may be sealed with suitable cohesive soils (i.e. clay)and/or a waterproof sealant, such as grout. For example, downstream oroutlet cut-off wall 550 may be sealed with a waterproof sealant.

FIG. 3 illustrates a closed bottom box culvert 501. Similar to theclosed bottom box culvert 500, box culvert 501 includes base panel 511,top panel 521, first side panel 531, second side panel 541, and cut-offwalls 551. First side panel 531 and second side panel 541 may extendfrom top panel 521 to base panel 511 to form passage 561. Box culvert501 may have been formed from box culvert 500 (as illustrated in FIG. 2). In box culvert 501, all plugs 514 from box culvert 500 have beenremoved, creating unsealed holes 516. Plugs 514 may be removed bypulling plugs 514 out of sealed holes 512, pushing plugs through sealedholes 512, drilling plugs 514 out of sealed holes 512, or any othermeans.

Box culvert 501 may present advantages over a traditional open andclosed bottom box culvert designs. In a traditional box culvert (such asbox culvert 100 of FIG. 1 ), natural life above the base panel 110 maybe displaced. Unsealed holes 516 allow for aquatic life to continue toexist by providing natural conditions. Further, unsealed holes 516 allowfor groundwater upwelling and drainage, while maintaining the integrityof base panel 510. Use of a cut-off wall 550 promotes ground waterupwelling into unsealed holes 516 by creating hydrostatic pressurearound box culvert 501. An increase in upwelling through holes 512allows for increased aquatic life, increased temperature gradient, andimproved drainage. Unsealed holes 516 may provide contact for conductivethermal transfer between riverbed and river.

However, increasing the number of unsealed holes 516 may still lead to adecrease in structural integrity in box culvert 501. For example, insome embodiments up to 50% of the area of base panel 511 may beperforated by unsealed holes 516 and still provide structural integrityin box culvert 501, with no required change to the preparation of basepanel 511. Additionally, groundwater upwelling may not be desirable ornatural at all unsealed holes 516 locations across base panel 511. Thismay lead to earlier replacement of box culvert 501.

FIG. 4 illustrates a closed bottom box culvert 502. Box culvert 502includes base panel 518, top panel 522, first side panel 532, and secondside panel 542. Base panel 518 includes cut-off walls 552. First sidepanel 532 and second side panel 542 may extend from top panel 522 tobase panel 518 to form passage 562.

Box culvert 502 contains both unsealed holes 516 and sealed holes 512.Box culvert 502 may be formed using box culvert 500 (as illustrated inFIG. 2 ). Based on a determination, the necessary plugs 514 in sealedholes 512 may be identified and removed, forming unsealed holes 516.Sealed hole 512 may have its plug 514 physically removed or knocked outusing mechanical means, depending on type of plug material and siteconditions.

The determination of which plugs 514 to remove may be based on multiplecharacteristics measured at an installation site. For example, a usermay measure water depth, water speed, water temperature, naturepresence, and ground hardness at predetermined positions across a river.Based on these measurements, the natural groundwater upwelling atspecific locations along a riverbed may be determined. Using thisinformation, the specific plugs 514 to remove may be identified. Forexample, if no natural groundwater upwelling is observed and/ordetermined, the sealed hole 512 may remain plugged. If a small amount ofgroundwater upwelling is observed and/or determined, a smaller sealedhole 512 may have its plug 514 removed. Similarly, if a large amount ofgroundwater upwelling is observed and/or determined, a larger sealedhole 512 may have its plug removed. Further, the determination may bebased on the weight of box culvert 502. It will be appreciated that plug514 may be removed from sealed hole 512 to create conditions forgroundwater upwelling in box culvert 502.

Groundwater upwelling may be determined to support the opening of sealedholes 512 to maximize performance of box culvert 502. Areas ofgroundwater upwelling may be determined based on stream assessment andnatural characteristics like watercress locations, visual upwellings anddifferences in surface water temperature. For example, testing forgroundwater upwelling may be achieved using streambed piezometers todetermine groundwater conditions and flow direction, which may also aidin the determination of which plugs 514 should be removed. Geotechnicaldata acquired from borehole observations may assist in determininggroundwater potential and typical elevation of groundwater in relationto road and creek level elevations. This geotechnical information may beused to determine the elevation of box culvert 502 relative to thestreambed. The elevation of base panel 518 may be set below the typicalheight of groundwater and at least 300 mm below the existing streambed.Groundwater input to the waterway may be within the bank and bed of thewatercourse so that when base panel 518 is placed below the streambedelevation the natural upward movement of groundwater may be forcedthrough unsealed holes 516 in optimal locations of base panel 518. Theconfiguration of sealed holes 512, relative to the configuration ofunsealed holes 516, may allow for controlled performance of box culvert502. As can be seen above, controlled performance of box culvert isdetermined from geotechnical data, elevation of groundwater, and habitatfeatures preferred by desired aquatic species.

Box culvert 502 may provide a benefit for aquatic life uponinstallation. By having unsealed holes 516 in optimal locations,groundwater upwelling may occur in a similar fashion to the habitat hadbox culvert not been installed. Thereby, aquatic life living in andtravelling through the culvert may observe minimal change in theirhabitat, including water temperature, water quality, velocity and flow.In addition, groundwater upwelling may also lead to spawning forgroundwater-dependent species (e.g. Brook trout). Controlled performanceof box culvert may also promote upwelling in locations that would nothave previously experienced upwelling, thereby creating a desiredhabitat in areas that were previously not supported.

As discussed above, box culvert 502 may have an inlet section and anoutlet section of passage 562. Cut-off walls 552 may be placed,respectively, under inlet section and outlet section of passage 562.Cut-off walls 552 may be solid, and may further include vertical pinsthat are pinned and grouted to inlet and outlet sections of passage 562.

In one embodiment, a technician may determine the configuration ofsealed holes 512, relative to the configuration of unsealed holes 516,based on an installation site mapping. The technician may generateinstallation site mapping based on a hydrogeology report describing theinstallation site, Global Positioning System (GPS) measurementscollected at installation site, and the physical characteristics of boxculvert 502.

A hydrogeologist may, for example, prepare hydrogeology report, based onhydrogeology analyses performed at the installation site. Hydrogeologistmay record the hydrogeological characteristics of the installation sitedescribed above, such as the locations of natural groundwater upwellingalong the riverbed of installation site, the elevation of groundwater inrelation to road and creek level elevation, and natural characteristicslike watercress locations, visual upwellings and differences in surfacewater temperature. Hydrogeology report may also recommend a location andorientation of box culvert 502 relative to installation site based onthe hydrogeological characteristics of installation site.

The technician may use a GPS device to log the hydrogeologicalcharacteristics of installation site described in the hydrogeologyreport. In particular, the technician may physically identify thehydrogeological characteristics from hydrogeology report at installationsite and collect GPS measurements for each of the hydrogeologicalcharacteristics. The technician may log the location of ahydrogeological characteristic of installation site using a GPSmeasurement of that hydrogeological characteristic. It will beappreciated that the technician may also optionally identifyhydrogeological characteristics of the installation site beyond thoseidentified in hydrogeology report, such that the technician may also useGPS device to collect GPS measurements for, and identify the locationof, each of these additional hydrogeological characteristics.

The location of a hydrogeological characteristic at the installationsite may represent a location at which it would be desirable to allow orprevent passage of water through the floor of box culvert 502. Thelocation of the hydrogeological characteristic may thus represent alocation at which it would be desirable to locate sealed holes 512 orunsealed holes 516 of box culvert 502, depending on the hydrogeologicalcharacteristic of installation site.

A technician may generate installation site mapping using the locationsof hydrogeological characteristics, as well as whether the location ofeach hydrogeological characteristic represents a location at which itwould be desirable to locate one or more sealed holes 512 or one or moreunsealed holes 516. For example, a first set of hydrogeologicalcharacteristics may correspond to locations where a small or largeamount of groundwater upwelling is observed, and so technician mayrecommend unsealed holes 516 of appropriate sizes at the locations offirst set of hydrogeological characteristics. A second set ofhydrogeological characteristics may correspond to locations where nogroundwater upwelling is observed, and so technician may recommendsealed holes 512 at the locations of second set of hydrogeologicalcharacteristics. The technician may record these recommendations ininstallation site mapping.

The technician may also record in installation site mapping arecommended location and orientation of box culvert 502 relative to theinstallation site. The technician may record in installation sitemapping the recommended location and orientation of box culvert 502relative to installation site by indicating preferred GPS locations oftwo or more corners of box culvert 502. It will be appreciated thattechnician may also record in installation site mapping the recommendedlocation and orientation of box culvert 502 relative to installationsite using some other suitable method.

In one embodiment, the technician may generate installation site mappingusing computer software. The technician may input into installation sitemapping software GPS measurements for each of the hydrogeologicalcharacteristics identified by the hydrogeology report and atinstallation site. In addition to GPS measurements, the technician mayinput into installation site mapping software a recommendation forwhether a sealed hole or an unsealed hole should be located at the GPSmeasurement for each hydrogeological characteristic. In furtherembodiments, the technician may also input into the installation sitemapping software a recommendation for the size of the unsealed hole orwhether multiple unsealed holes may be required. The technician mayfurther manually identify a specific number or area of unsealed holesthat may be required. Recommendations for the size and number ofunsealed holes may be based on the geotechnical data, elevation ofgroundwater, and habitat features preferred by desired aquatic species.

The technician may input into installation site mapping software therecommended orientation and location of box culvert 502, such as byinputting the preferred GPS locations of two or more corners of boxculvert 502. As well, the technician may also input into installationsite mapping software the physical characteristics of box culvert 502.For example, the technician may input a serial number, quick response(QR) code or other identifier of box culvert 502 into installationmapping software, or technician may select the physical characteristicsof box culvert 502 from a list of possible box culvert configurations.In this way, technician may enable installation site mapping software toidentify the physical characteristics of box culvert 502. Alternatively,technician may manually input into installation site mapping softwarethe physical characteristics of box culvert 502.

In further embodiments, instead of the technician inputting arecommendation for whether a sealed hole or an unsealed hole should belocated at the GPS measurement for each hydrogeological characteristic,the technician may input into installation site mapping softwaredescriptive information for each hydrogeological characteristic. Forexample, descriptive information may include whether the hydrogeologicalcharacteristic corresponds to a location where a small, medium or largeamount of groundwater upwelling is observed or where no groundwaterupwelling is observed. The technician may select descriptive informationfrom a list of possible descriptive information categories ininstallation site mapping software. For each hydrogeologicalcharacteristic, installation site mapping software may automaticallyrecommend whether a sealed hole 512 or an unsealed hole 516 should beformed in box culvert 502, based on the descriptive informationassociated with that hydrogeological characteristic. Installation sitemapping software may include a lookup table correlating each descriptiveinformation category in list of possible descriptive informationcategories with a recommendation for a sealed hole or an unsealed hole.In further embodiments, lookup table may also include a recommendationfor the size of the unsealed hole and whether multiple unsealed holesare required.

The technician may run or execute installation site mapping software,such that installation site mapping software may automatically determinesealed holes 512 and unsealed holes 516 to be formed in box culvert 502,based on the inputs into installation site mapping software describedabove. For example, installation site mapping software may firstdetermine the GPS locations of box culvert 502 based on the recommendedorientation and location of box culvert 502 and the physicalcharacteristics of box culvert 502, both input into installation sitemapping software. The GPS locations of box culvert 502 may include theGPS location of two or more corners of box culvert 502, or the GPSlocations of several points around the perimeter of box culvert 502. TheGPS locations of box culvert 502 may also include the GPS locations ofsealed holes 512, which may be unsealed to form unsealed holes 516 inbox culvert 502. Installation mapping software may compare the GPSmeasurement for each hydrogeological characteristic to the GPS locationsof sealed holes 512. For each hydrogeological characteristic thatincludes a recommendation for an unsealed hole, installation sitemapping software may determine which sealed hole 512 is closest and canbe unsealed to form unsealed hole 516 in box culvert 502. In someembodiments, installation site mapping software may also determine whichmultiple sealed holes 512 close to the GPS measurement for thehydrogeological characteristic, which can all be unsealed to formunsealed holes 516 in box culvert 502. Similarly, for eachhydrogeological characteristic that includes a recommendation for asealed hole, installation site mapping software may determine whichsealed hole 512 is closest and should remained sealed. In this way,installation site mapping software may automatically determine sealedholes 512 and unsealed holes 516 to be formed in box culvert 502. Itwill be appreciated that installation site mapping software mayautomatically make this determination in a different order or usingother method steps not described above.

It will be appreciated that technician or installation site mappingsoftware may also manually determine sealed holes 512 and unsealed holes516 to be formed in box culvert 502 based on the hydrogeology reportdescribing the installation site, GPS measurements collected atinstallation site, and the physical characteristics of box culvert 502and the surrounding environment.

In some embodiments, at least one of cut-off walls 552 may be include anopening. For example, cut-off wall 552 placed under inlet section ofpassage 562 may be an upstream or inlet cut-off wall. Box-culvert 502may include one or more openings located in the uppermost half of inletcut-off wall 552 to allow for waterflow into the bedding below boxculvert 502. One or more openings located in cut-off wall 552 mayinclude perforations to allow water to travel through inlet cut-off wall552. The bedding may be clear stone bedding.

Cut-off wall 552 placed under outlet section of passage 562 may be adownstream or outlet cut-off wall. To ensure the lateral flow ofgroundwater, it may be desirable for groundwater in the bedding of thewaterway to flow upward through unsealed holes 516 and into passage 562.This may be achieved by cut-off wall 552 remaining solid, and also byback-filling cut-off wall 552 with native or compacted cohesive materialaround its edge to ensure a seal that promotes upward flow throughunsealed holes 516.

Base panel 518 may be layered with a suitable granular substrate, andgroundwater may flow upward through both unsealed holes 516 and granularsubstrate. It will be appreciated that nominal sized stone is requiredto ensure that the formed creek bed remains in the culvert and tied intothe upstream and downstream channel of box culvert 502. As well,granular substrate may allow free flow of groundwater based on the porespacing within granular substrate. According to one embodiment, granularsubstrate may be sized based on hydraulics, such as the diameter andpercentage of stone that may be required to ensure that substrate willnot be flushed out of the culvert. Granular substrate may also need tobe free of granular fines, such as clay and silt, to allow forgroundwater movement through granular substrate from unsealed holes 516.For example, granular substrate may consist of nominal sized stone, suchas large gravel, cobble, and boulder, with a lower percentage of mediumto fine gravel and sand. Granular substrate may be a clear stone gravelpack.

FIG. 5A illustrates a cross-sectional view of base panel 518 along lineA-A in a box culvert (such as box culvert 502), according to oneembodiment. As may be seen, unsealed holes 516 and plugs 514 extendvertically from a top side of base panel 518 to a bottom side. As may befurther observed, the two leftmost holes and the rightmost hole areunsealed holes 516. The remainder of holes in the row illustrated in thecross section are sealed holes 512 contain plugs 514. However, asillustrated, the configuration of other rows may be different.

While the illustrated plugs 514 extend from the top side to the bottomside of base panel 518, plugs 514 may be configured to only extendpartially through the sealed hole 512.

Plugs 514 may be removed by pushing plugs 514 out of sealed holes 512,pulling plugs out of sealed holes 512, drilling plugs 514 out, or anyother means.

FIG. 5B illustrates a cross-sectional view of base panel 518′ along lineA-A in a box culvert (such as box culvert 502), according to anotherembodiment. In this embodiment, sealed holes 512′ having plugs 514′, andunsealed holes 516′ have been formed into base panel 518′ at an angle.While the illustrated sealed holes 512′ and unsealed holes 516′ are allshown having the same angle directed inwardly, each sealed hole 512′,plug 514′ and unsealed hole 516′ may be configured in base panel 518′ tohave a unique and variable angle. For example, holes closer to firstside panel 532 and second side panel 542 may have greater angles thanthose closer to the center of base panel 518′.

Similar to plugs 514, plugs 514′ may be removed by pushing, pulling,drilling, or any other means.

FIG. 5C illustrates a cross-sectional view of base panel 518″ along lineA-A in a box culvert (such as box culvert 502), according to anotherembodiment. In this embodiment, sealed holes 512″ are sealed usingknockout panels. Knockout panels 524 may be made of the same material asbox culvert 502, or a different material that can be removed orpartially removed, such as concrete, foam, rubber, and may includescreens in unsealed holes 516.

Knockout panels 524 may be thinner than the base panel 518, such thatsealed holes 512″ may be opened by drilling, hammering, jackhammering,or any other means. Use of a thinner material than base panel 518″allows for easily unsealing sealed holes 512″ using less force thandrilling through the entire base panel 518″.

FIG. 6 illustrates box culvert 502 in an installed position. As may beobserved, river 612 is flowing through passage 562, while road 300 ispositioned over top panel 522. Groundwater may come through unsealedholes 516, while it may not go through sealed holes 512.

In further embodiments, box culvert 502 may include variations ofunsealed holes 516. For example, box culvert 502 may include screenedunsealed holes 516 to deter fine sediments from settling inside unsealedholes 516. Box culvert 502 may also have conical unsealed holes 516 witha small diameter oriented at the top of base panel 518 to increase thevelocity of upwelling groundwater. As well, box culvert 502 may includelouver-type unsealed holes 516.

FIG. 7 illustrates a method of installing a box culvert.

At step S102, box culvert having sealed holes in a base panel (such asthe box culvert 500 shown in FIG. 2 ) is provided. The sealed holes maybe sealed using removable plugs, knockout panels, a combination thereof,or by other sealing means. Sealed holes may have different sizes,positions, and angles, and may be cast into a base panel of the boxculvert.

At step S104, based on a determination for the installation site, atleast one hole to unseal is selected. The determination to identify theat least one hole to unseal may be based on water depth, water speed,water temperature, nature presence, ground hardness, and hydraulicpressure measured at the installation site. Measurements may be taken atmultiple points along an installation site. Based on these measurements,sealed holes (having a size, position, or angle) may be identified orselected. The selection may be further based on the available holes.

It will be appreciated that in some embodiments, the determination toidentify at least one hole to unseal may be based on an installationsite mapping. Installation site mapping may be generated based on ahydrogeology report describing the installation site, GPS measurementscollected at installation site, and the physical characteristics of boxculvert, according to one of the embodiments described above. Forexample, installation site mapping software may be used to automaticallydetermine at least one hole to unseal.

At step S106, the at least one hole is unsealed. The at least one holemay be unsealed by pushing out a plug, pulling out a plug, drilling outa plug or knock-out panel, hammering out a knock-out panel, or any othermeans. The plugs may be removed at a location close to the installationsite. Alternatively, plugs may be removed at an offsite location.

At step S108, the box culvert may be installed at the installation site.According to some implementations, the box culvert may be installed bylifting the culvert from a nearby location with a crane or other means,then placing the culvert in the waterway.

After installation, culvert may include a clear stone bedding orsubstrate below the culvert having a suitable depth (generally 0.3 m)and porosity to convey groundwater flow. Sections of the culvert may beproperly sealed, an inlet cut-off wall may include one or more openingsand be properly backfilled, and an outlet cut-off wall may be sealed.For example, the last section of culvert may be properly sealed withcohesive materials to allow flow through the clear stone gravel pack andinto the sized openings in the base panel of the culvert. The typicalspecified streambed material is granular (sand, gravel and cobble) andallows movement of groundwater from the openings in the base panel,through the streambed material and into the stream, providingimprovements to the aquatic conditions.

FIG. 8 illustrates a cross-sectional view of a box culvert 800 installedinto stream bed 804. Box culvert 800 includes top panel 820 and basepanel 810. Base panel 810 includes both sealed holes 812 and unsealedholes 816. Base panel 810 also includes inlet cut-off wall 830 a andoutlet cut-off wall 830 b. In addition to seal holes 812 and unsealedholes 816 in base panel 810, inlet cut-off wall 830 a may furtherinclude opening 832. Passage 862 is formed between top panel 820 andbase panel 810, allowing stream water 860 to flow into box culvert 800.Stream flows in downstream direction 814.

Granular substrate 880 a may be layered on the stream bed 804 below basepanel 810 of box culvert 800. Similarly, granular substrate 880 b may belayered onto the surface of base panel 810. The thickness of granularsubstrate 880 a below base panel 810 may depend on depth of installationH of box culvert 800 and the height of base panel 810 from stream bed804. The thickness of granular substrate 880 b on top of base panel 810may be chosen to match the height of the bottom of stream 860, such thatthe depth of stream 860 within and outside of passage 862 is the same.In some embodiments, one or both of granular substrate 880 a and 880 bmay be clear stone bedding.

It will be appreciated that inlet and outlet cut-off walls 830 a and 830b may extend deeper into stream bed 804 than does granular substrate 880a, such as to provide additional structural support to box culvert 800.For example, cut-off walls 830 a and 830 b may extend up to 1 m deepinto stream bed 804, and may also be approximately 30 cm thick in thedownstream direction 814. Cut-off walls 830 a and 830 b may also extendacross the entire width of box culvert 800 in the direction transverseto downstream direction 814. In other embodiments, cut-off walls 830 aand 830 b may be installed at depths greater than 1 m and manufacturedat greater or smaller thicknesses, depending on the physicalcharacteristics of the installation site.

In some embodiments, the temperature and flow of groundwater input 834into passage 862 may be controlled by depth of installation H of boxculvert 800. Generally, the temperature of groundwater may be differentthan the temperature of stream water 860. For example, in colderclimates, groundwater may be warmer than stream water 860, while inwarmer climates groundwater may be colder than stream water 860.

As noted already, inlet cut-off wall 830 a placed under inlet section ofpassage 862 may include opening 832. Opening 832 may include one or moreopenings, which may be perforations, channels, holes or other featuresthat allow water to travel through inlet cut-off wall 830 a. Opening 832may be in the uppermost half of cut-off wall 830 a to allow forgroundwater input 834 to flow into the bedding below box culvert 800.The deeper cut-off wall 830 a and its opening 832 are installed into theground, the colder or warmer the temperature of groundwater input 834into the granular substrate 880 a may be. In some other embodiments,inlet cut-off wall 830 a may include opening 832 in the lowermost halfof cut-off wall 830 a, or in both the uppermost and lowermost halves.The size or total area of opening 832 may be chosen such that theopening does not impede the flow of input groundwater 834 through inletcut-off wall 830 a.

Groundwater may enter granular substrate 880 a transversely todownstream direction 814. For example, the native soil of stream bed 804may be saturated with water. However, in addition to this groundwatertraveling transversely to downstream direction 814, some stream water860 may flow underneath the upper surface of stream bed 804 indownstream direction 814. Opening 832 in inlet cut-off wall 830 a mayensure that this groundwater travelling in downstream direction 814 canenter granular substrate 880 a beneath base panel 810 and eventuallytravel through unsealed holes 816 into passage 862 of box culvert 800.In particular, groundwater input 834 may flow through opening 832 ininlet cut-off wall 830 a and into granular substrate 880 a. Since outletcut-off wall 830 b may not include any openings, groundwater may notexit from below base panel 810 through outlet cut-off wall 830 b.Instead, groundwater may only exit through stream bed 804 or unsealedholes 816. It will be appreciated that by providing a sufficient numberof unsealed holes 816 in base panel 810, most groundwater may exitthrough unsealed holes 816 and into granular substrate 880 b above basepanel 810. This groundwater may eventually flow upward into passage 862of box culvert 800 and mix with stream 860.

Technician or mapping software may determine the number and size ofunsealed holes 816 based on the difference in temperature between thegroundwater and the stream, as well as the relative flow rates betweengroundwater input 834, groundwater 804 and stream 860. For example, flowrate may be represented by Darcy's Law, as follows:

Q=−KAΔP  (Equation 1)

where K is the hydraulic conductivity, A is the cross-sectional areathrough which the flow is being assessed, and ΔP is the drivingforce/difference in pressure.

Equation 1 may be used to estimate the flow through several surfaces.Water flows from an undisturbed point upstream of box culvert 800. Waterflows from the native soil of stream bed 804, through the upstream wallof box culvert 800, granular substrate 880 a and 880 b, downstream wallof box culvert 800, downstream gravel, and downstream native soil. Whilein granular substrate 880 a, there may be additional flow from thenative soil of stream bed 804 on the sides and bottom of the granularsubstrate 880 a and through the top of granular substrate 880 a into theinterior of the box culvert 800 through unsealed holes 816.

Equation 1 may be used to estimate the flow through each of theseplanes. However, the number of equations may be minimized based on thefollowing observations. For example, in the area upstream of box culvert800 at the interface between the native soil of stream bed 804 andgranular substrate 880 a of the inlet cut-off wall, two equations may beconsidered: the equation for water leaving the native soil of stream bed804 and the equation for water travelling through the granular substrate880 b. The hydraulic conductivity of the clear stone in granularsubstrate 880 a may be much higher than the hydraulic conductivity ofthe native soil of stream bed 804, so the flow through the clear stonegravel pack may be limited by the flow out of the native soil. This samelimited flow may pass through inlet cut-off wall 830 a, and inparticular through opening 832, and into granular substrate 880 a.Consequently, it may be assumed that the flow of water travellingthrough the granular substrate 830 a will be equal to the flow of waterleaving the native soil of stream bed 804, such that the number ofequations may be reduced to only one, namely the equation describing theflow leaving the native soil of stream bed 804. It is assumed that thegravel upstream of inlet cut-off wall 830 a may be confined by a muchless permeable material typical of the bottom of the stream.

On the downstream end of box culvert 800, the outlet cut-off wall 880 bmay be impermeable, such that there will not be any flow through outletcut-off wall 830 b. Similarly, outlet cut-off wall 880 b may be properlysealed to ensure that no water can enter through the connection pointbetween cut-off wall 880 b and base panel 810.

All the water flowing into granular substrate 880 a may come from nativesoil of stream bed 804. This water will flow through unsealed holes 816in base panel 810 and into the streambed 860. The flow of water intogranular substrate 880 a is equal to the sum of the flows from thesurrounding ground, namely the stream bed 804:

Q _(GP) =Q _(g) +Q _(h)  (Equation 2)

where Q_(GP) is the flow of water from the granular substrate into thestream 860, Q_(g) is the flow of water from the surrounding ground intogranular substrate 880 a and Q_(h) is the flow of water from upstreaminto granular substrate 880 a through opening 832.

Substituting Equation 2 into Equation 1 produces:

Q _(GP)=(−K _(g) A _(g) ΔP _(g))+(−K _(h) A _(h) ΔP _(h))  (Equation 3)

where K_(g) is the hydraulic conductivity of the ground around boxculvert 800, A_(g) is the area of ground below and to either side of boxculvert 800 (not upstream or downstream), ΔP_(g) is the ground hydraulicpressure or driving force pushing water from ground into granularsubstrate 880 a, K_(h) is the hydraulic conductivity of the groundupstream (hyporheic zone) of box culvert 800, A_(h) is the area ofgravel upstream of inlet cut-off wall 830 a of box culvert 800, andΔP_(h) is the hyporheic hydraulic pressure pushing water from hyporheiczone through opening 832 of inlet cut-off wall 830 a into granularsubstrate 880 a.

If the hydraulic conductivity of the native soil is uniform throughoutthe installation, the hydraulic conductivity of the native soil ofstream bed 804 beside and below granular substrate 880 a may be the same(K_(g)=K_(h)). As well, if the hydraulic pressure of the native soil isuniform throughout the installation, the hydraulic pressure of the soilof stream bed 804 beside and below the granular substrate 880 a may bethe same (ΔP_(g)=ΔP_(h)). Equation 3 can thus be simplified, as follows:

Q _(GP) =−K _(g)(A _(g) +A _(h))ΔP _(g)  (Equation 4)

Since the areas A_(g) and A_(h) are known, the only remaining unknownsare K_(g) and ΔP_(g). However, K_(g) can be estimated from the soil typeof the surrounding soil and ΔP_(g) may be measured prior to the designof box culvert 800 for a given location. As such, Equation 4 can be usedto calculate Q_(GP).

Once Q_(GP) is calculated, the number and size of unsealed holes 816 maybe determined based on the difference in temperature between thegroundwater and the stream, as well as the relative flow rates betweenthe groundwater and the stream. The number of unsealed holes 816 mayprovide sufficient discharge zones to maximize the number of spawninglocations for desired aquatic wildlife. If Q_(GP) is equal to the flowof the stream, then many sealed holes 812 may be unsealed in box culvert800. However, Q_(GP) is typically much smaller than the flow of thestream, so the number of holes may be limited.

As noted already, since Q_(GP) may be determined by the hydraulicconductivity of the surrounding ground and the flow of the stream may berelated to the slope of the land, it may be expected that Q_(GP) will bemuch less than the flow of the stream. For example, if it is assumedthat Q_(GP) is 1% of the flow of the stream, and it is assumed thatthere is a single unsealed hole 816 in base panel 810 of box culvert 800and a stream flow rate of 100 L/min, then Q_(GP) will be 1 L/min. As thewater flows up through the bottom of box culvert 800, the watertemperature may match the groundwater temperature because it will nothave had any opportunity to mix with the stream water. As this watergets close to the surface of the stream, both waters will mix and createa separate temperature pool. The resulting temperature difference couldbe insignificant or greatly increase, depending on the relativetemperatures between the groundwater and the stream water. Thistemperature difference is critical in creating a localized environmentthat supports spawning and the sustainability of aquatic life. If it isassumed that the stream temperature is 15° C. and the groundwatertemperature is 10° C., the stream temperature just downstream from wherethe groundwater enters will be 100 L/min×15° C.+1 L/min×10° C./101L/min=14.95° C., which may be undetectable. However, if the entry pointis a depression in the stream bottom and it is protected by a big rockor loose gravel, then the temperature could be closer to the groundwater temperature.

It will be appreciated the number of unsealed holes 816 may be relatedto the calculated flow and the flow rate of the stream through boxculvert 800. The number and size of unsealed holes 816 may be determinedbased on the calculations described above. Alternatively, othercalculations may be used to determine the number and size of unsealedholes 816.

In some further embodiments, the number and size of unsealed holes 816may also be determined based on the velocity required to keep sand andfines from settling on base panel 810, since some desired aquaticspecies do not like a mucky bottom. The total size of unsealed holes 816may be chosen such that the total velocity of groundwater coming upthrough unsealed holes 816 is high enough to keep sand from settlingaround unsealed holes 816. For example, if the velocity of water passingthrough unsealed holes 816 is higher than the terminal velocity for aparticle, then the particle cannot settle in the flow. It will beappreciated that a smaller total area of unsealed holes 816 may resultin a higher velocity for groundwater particles, thus preventing sand andfines from settling in the unsealed holes 816. This velocity may furtherprevent the settling of sand and fines in selected areas on base panel810, providing areas clear of a mucky bottom.

Although the present invention has been described with reference tospecific features and embodiments thereof, various modifications andcombinations can be made thereto without departing from the invention.The description and drawings are, accordingly, to be regarded simply asan illustration of some embodiments of the invention as defined by theappended claims, and are contemplated to cover any and allmodifications, variations, combinations or equivalents that fall withinthe scope of the present invention. Therefore, although the presentinvention and its advantages have been described in detail, variouschanges, substitutions, and alterations can be made herein withoutdeparting from the invention as defined by the appended claims.Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, composition of matter, means, methods and steps describedin the specification. As one of ordinary skill in the art will readilyappreciate from the disclosure of the present invention, processes,machines, manufacture, compositions of matter, means, methods, or steps,presently existing or later to be developed, that perform substantiallythe same function or achieve substantially the same result as thecorresponding embodiments described herein may be utilized according tothe present invention. Accordingly, the appended claims are intended toinclude within their scope such processes, machines, manufacture,compositions of matter, means, methods, or steps.

What is claimed is:
 1. A box culvert, comprising: a top panel; a basepanel; and a first and second side panel extending from the top panel tothe bottom panel; wherein the base panel has a plurality of sealedholes, each hole configured to be unsealed.
 2. The box culvert of claim1, wherein the sealed holes each comprise a plug.
 3. The box culvert ofclaim 1, wherein the sealed hole is a knockout panel.
 4. The box culvertof claim 2, wherein the sealed holes each further comprise a sealantconfigured to hold the plug in the hole.
 5. The box culvert of claim 4,wherein the sealant is a wax or a caulk.
 6. The box culvert of claim 2,wherein the plug is integrally formed in the box culvert.
 7. The boxculvert of claim 2, wherein the plug is made of a different materialthan the box culvert.
 8. The box culvert of claim 1, wherein the sealedholes are a through holes extending perpendicularly from a first planeto a second plane of the base panel.
 9. The box culvert of claim 1,wherein the sealed holes are angled.
 10. The box culvert of claim 1,wherein the box culvert is concrete.
 11. The box culvert of claim 1,wherein the base panel has an inlet cut-off wall extending across aninput end of the base panel and an outlet cut-off wall extending acrossan output end of the base panel.
 12. The box culvert of claim 11,wherein the inlet cut-off wall includes one or more openings forgroundwater to pass through the inlet cut-off wall and the outletcut-off wall is configured to be impermeable.
 13. A method of installinga box culvert, comprising: providing a box culvert having sealed holesin a base panel; selecting, based on a determination for an installationsite, at least one sealed hole to be opened; opening the seal of theselected at least one sealed hole to be opened; and installing the boxculvert.
 14. The method of claim 13, wherein the sealed holes are sealedusing plugs.
 15. The method of claim 13, wherein the sealed holes aresealed using knockout panels.
 16. The method of claim 13, wherein thedetermination is based on at least one of the water depth, the waterspeed and the water temperature at at least one location in theinstallation site.
 17. The method of claim 13, wherein the determinationis based on at least one of the diameters of the sealed holes, theangles of the sealed holes, the position of the sealed holes and adesired velocity of water particles to prevent sand from settling on thebase panel.
 18. The method of claim 14, wherein the opening the sealcomprises removing the plug.
 19. The method of claim 14, wherein theopening the seal comprises removing the knockout panel.
 20. The methodof claim 14, wherein the sealed holes are angled.